IMAGE  EVALUATION 
TEST  TARGET  (MT-3) 


1.0 


I.I 


Li  128     12.5 

US  Uii   12.2 

u    lil 

2.0 


us 


IM 


1.8 


^      ill 

L25  i_U  11.6 


/A 


^<V 
^ 


/ 


Photographic 

Sciences 

Corporation 


23  WEST  MAIN  STREET 

WEBSTER,  N.Y.  MS80 

(716)  873-4503 


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(V 


•N? 


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1^. 


6^ 


€>. 


>> 


i/. 


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CIHM/ICMH 

Microfiche 

Series. 


CIHM/ICIVIH 
Collection  de 
microfiches. 


Canadian  Institute  for  Historical  Microreproductions  /  Institut  Canadian  de  microreproductions  historiques 


Technical  and  Bibliographic  Notaa/Notaa  tachniquaa  at  bibliographiquaa 


Tha  Inatituta  haa  attamptad  to  obtain  tha  baat 
original  copy  availabia  for  filming.  Faaturaa  of  thia 
copy  which  may  ba  bibliographicaily  uniqua, 
which  may  altar  any  of  tha  imagaa  in  tha 
raproduction.  or  which  may  aignificantly  changa 
tha  uaual  mathod  of  filming,  ara  chackad  balow. 


□    Colourad  covara/ 
Couvartura  da  coulaur 


I — I    Covara  damagad/ 


D 


D 


D 
D 


n 


121 


Couvartura  andommagia 


Covara  raatorad  and/or  laminatad/ 
Couvartura  raataurte  at/ou  palliculAa 


I — I   Covar  titia  miaaing/ 


La  titro  da  couvartura  manqua 


I — I    Colourad  mapa/ 


Cartaa  gtographiquaa  an  coulaur 


Colourad  ink  (i.a.  othar  than  blua  or  black)/ 
Encra  da  coulaur  (i.a.  autra  qua  blaua  ou  noira) 


I     I   Colourad  plataa  and/or  illuatrationa/ 


Planchaa  at/ou  illuatrationa  an  coulaur 


Bound  with  othar  matarial/ 
Rail*  avQC  d'autraa  documanta 


Tight  binding  may  cauaa  ahadowa  or  diatortion 
along  intarior  margin/ 

La  re  iiura  aarrAa  paut  cauaar  da  I'ombra  ou  da  la 
diatoraion  la  long  da  la  marge  intArieure 

Blank  laavaa  added  during  reatoration  may 
appear  within  the  text.  Whenever  poaaibia,  theae 
have  been  omitted  from  filming/ 
II  aa  paut  que  certainaa  pagea  blanchaa  ajoutiea 
iora  d'une  reatauration  apparaiaaent  dana  la  taxte. 
maia.  loraqua  cela  Atait  poaaibia,  caa  pagea  n'ont 
pea  it*  fiimiaa. 


Additional  commanta:/ 
Commantairea  supplAmantairaa: 


L'Inatitut  a  microfilm*  la  meilleur  exempiaira 
qu'il  lui  a  it*  poaaibia  da  aa  procurer.  Lea  details 
da  cat  exempiaira  qui  aont  paut-*tre  uniquea  du 
point  de  vue  bibliographiqua,  qui  peuvent  modifier 
une  image  reproduite.  ou  qui  peuvent  exiger  une 
modification  dana  la  mithoda  normale  de  filmage 
aont  indiquia  ci*deaaoua. 


T 
t( 


r*n   Coloured  pegea/ 


n 


Pagea  de  couleur 

Pagea  damaged/ 
Pagea  andommagiaa 


□   Pagea  raatorad  and/or  laminated/ 
Pagea  reatauriaa  et/ou  pelliculiea 

Q   Pagea  diacoiourad,  stained  or  foxed/ 
Pagea  dicolorias.  tachaties  Ob  piquias 

r~7|   Pagea  detached/ 
uLi   Pagea  d*tach*es 

Showthrough> 
Tranaparance 

Quality  of  prir 

Qualit*  inigala  de  I'impression 

Includea  supplementary  materii 
Comprend  du  metiriel  suppiimentaira 

Only  edition  available/ 
Seuia  idition  disponible 


1 

P 

0 

f 


b 
t 

a 
o 
f 

s 


r~y\  Showthrough/ 

I      I  Quality  of  print  variea/ 

r~n  Includea  supplementary  material/ 

rn  Only  edition  available/ 


T 

ai 
T 

VI 

d 

b( 
ri 
ri 
nr 


Pagea  wholly  or  partially  obscured  by  errata 
slips,  tissues,  etc..  have  been  refiimed  to 
ensure  the  best  possible  image/ 
Lea  pagea  totalement  ou  partiailement 
obscurciea  par  un  feuillet  d'errata,  une  pelure, 
etc.,  ont  *t*  filmies  *  nouveau  da  fapon  A 
obtanir  la  meilleure  image  poaaibia. 


Psgination  as  follows  :  239-253  p. 


Thia  item  is  filmed  at  the  reduction  retio  checked  below/ 

Ce  document  est  film*  au  taux  de  r*duction  indiqu*  ci-dessous. 

10X  14X  18X  22X 


26X 


30X 


. 

y 

12X 


16X 


20X 


24X 


28X 


32X 


Stalls 
IS  du 
nodifier 
n  una 
ilmaga 


IS 


Th«  copy  filmad  h«r«  hm  b««n  r«produc«d  thanks 
to  th«  g«n«ro«ity  of: 


L6giilature  du  Qutbee 
QuAec 

Tho  imagos  appearing  hara  ara  tha  baat  quality 
posaibia  conaidaring  tha  condition  and  iagibility 
of  tha  original  copy  and  in  Icaaping  with  tha 
filming  contract  apacificationa. 


Original  copiaa  in  printad  papar  eovara  ara  filmad 
beginning  with  tha  front  covar  and  anding  on 
tha  laat  paga  with  a  printad  or  illuatratad  impraa- 
sion,  or  tha  bacic  covar  whan  appropriate.  All 
othar  original  copiaa  ara  filmad  beginning  on  tha 
first  paga  with  a  printad  or  Illuatratad  impraa- 
sion,  and  anding  on  tha  laat  page  with  a  printad 
or  illuatratad  impreaaion. 


Tha  laat  recorded  frame  on  eech  microfiche 
shall  contain  the  symbol  —►(meaning  "CON- 
TINUED"), or  tha  symbol  V  (meaning  "END"), 
whichever  appliaa. 

Mapa,  plataa.  charta.  etc..  mey  be  filmed  at 
different  reduction  ratioa.  Thoae  too  large  to  be 
entirely  included  in  one  expoaura  are  filmed 
beginning  in  the  upper  left  hand  comer,  left  to 
right  and  top  to  bottom,  aa  many  framea  aa 
required.  The  following  diagrama  illuatrata  the 
method: 


L'exemplaira  fiimA  fut  reproduit  grice  A  la 
ginAroait*  da: 

L^iilature  du  Quebec 
QuMmc 

Lea  imagea  auivantae  ont  #t*  reproduitea  avac  le 
plua  grand  aoin,  compta  tenu  de  la  condition  at 
de  la  netteti  de-l'exemplaira  film*,  at  en 
conformity  avac  lee  condltiona  du  contrat  da 
filmage. 

Lea  axempleirea  origlnaux  dont  la  couvarture  en 
papier  eat  ImprimAa  aont  filmte  an  commandant 
par  le  premier  plat  at  en  terminant  soit  par  la 
darnlAre  page  qui  comporte  une  empreinte 
d'impreaaion  ou  d'illuatration,  soit  par  la  second 
plat,  salon  le  caa.  Toua  lea  autras  axampiairea 
origlnaux  aont  filmto  an  commen^ant  par  la 
premlire  paga  qui  comporte  une  empreinte 
d'impreaaion  ou  d'illuatration  at  en  terminant  par 
la  darnlAre  paga  qui  comporte  une  telle 
empreinte. 

Un  dea  aymbolaa  auivanta  apparattra  sur  la 
darnMre  image  de  cheque  microfiche,  selon  le 
caa:  la  aymboia  -^  signifie  "A  SUIVRE".  le 
symbols  ▼  signifie  "FIN". 

Les  cartea,  planchee,  tableaux,  etc.,  peuvent  Atre 
fiimia  A  dea  taux  da  rAduction  diff Aranta. 
Loraqua  le  document  eat  trop  grand  pour  Atre 
reproduit  en  un  seul  clichA,  11  est  f llmA  A  partir 
da  I'angia  aupAriaur  gauche,  de  gauche  A  droite, 
et  de  haut  mn  baa,  en  prenant  la  nombra 
d'imegea  nAcaasaire.  Les  diagrammea  auivanta 
illuatrant  la  mAthode. 


errata 
to 


pelure. 
>n  A 


n 

32X 


1 

2 

3 

1 

2 

3 

4 

5 

6 

■-;*»'i„ii«'*'-;,''^' 


^■0 


TlIK 


TAOOlCiC  AMD  M)mE  SILUBIAK  BO^ 


J       »■         >*_        7«r 


:■}> 


,  > 


<»» 


TBKtONl:'  WT)  ,to^^: 


i-  .  •*. 


BT  hlM  MAECOir. 


BOSTON: 

F&ESS    OF    GEO.    0.    BAND    ft    AVEBT 


.  >fj 


.  /.!;F 


M 


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it 


,11 
1 


-  o!l 


1 


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239 


The  Taconic  and  Lower  Silurian  Rocks  of  Vermont  and 
Canada.  By  Jules  Marcou. 

At  the  meeting  of  Oct.  17,  18C0, 1  bad  the  honor  to  read  before  the 
Society  extracts  from  three  letters  of  M.  Barrande,  relating  to  the 
stratigraphical  position  of  the  primordial  fauna  in  North  America. 
Two  of  those  letters  were  addressed  to  me,  the  third  was  a  copy  of  a 
letter  to  Professor  Bronn  of  Heidelberg.  I  added  a  few  remarks,  and 
the  whole  was  published  in  the  Proceedings,  Vol.  vii.  p.  369,  under  the 
title,  "On  the  Primordial  Fauna  and  the  Taconic  Systein,  by  Joachim 
Barrande,  tvith  additional  notes  by  Jules  Marcou." 

The  views  there  exposed  were  received  with  little  favor,  at  first,  by 
those  geologists  who,  for  the  last  fifteen  years,  have  refused  to  recog- 
nize the  Taconic  system,  on  the  ground  that  it  was  not  sustained  by 
any  stratigraphical,  paleontological,  or  lithological  evidence.  Ic  was 
hard  for  them  to  admit  that  the  paleontological  character  at  least  was 
against  them,  some  going  so  far  even  as  to  deny  the  validity  of  pale- 
ontological evidence  in  determining  the  age  of  strata.  As  the  same 
persons  have  long  considered  the  lithological  character  "  entirely 
valuelesa,"  American  geology  was  deprived  of  its  two  best  supports, 
and  left  entirely  at  the  mercy  of  suppositions  and  conjectures.  It  was 
evident,  however,  that  the  summary  method,  so  frequently  used,  of 
suppressing  observations  which  did  not  agree  with  the  views  of  those 
regarded  by  some  as  the  best  and  highest  authorities  on  this  continent, 
could  not  succeed  now,  as  it  was  impossible  to  rule  out  the  science  of 
paleontology  and  its  supporters. 

Three  months  later,  Mr.  Logan  of  Montreal,  in  a  letter  to  M. 
Barrande  (in  which  he  inadvertently  omitted  to  mention  our  Boston 
pamphlet),  admits  that  the  views  entertained  by  him  on  the  rocks  of 
Point  Levi  and  Georgia  were  erroneous,  and  tries  to  explain  the 
position  of  strata  at  Point  Levi,  putting  together  all  the  rocks  found 
there,  as  the  "  Quebec  group  of  rocks." 

Mr.  James  Hall,  of  Albany,  in  a  letter  to  the  editor  of  Silliman's 
Journal,  one  month  later,  takes  up  the  paleontological  evidence, 
letting  it  be  understood  that,  if  any  mistake  was  made,  it  was  due  to 
stratigraphy ;  and  mixing  together,  even  more  than  Mr.  Logan  had 
done,  all  the  fossils  found  in  the  various  places  and  strata  at  Point 
Levi,  he  comes  to  the  conclusion  that  ''  M.  Barrande's  plan  of  succes- 
sive Trilobitic  faunaj "  does  not  meet  the  case  in  hand ;  and,  without 
giving  any  decisive  opinion,  he  evidently  leans  toward  the  view  that 
he  has  always  entertained,  in  common  with  the  Professors  Rogers,  of 
the  Hudson  River  group. 

This  letter  of  Mr.  James  Hall  appeared  in  Silliman's  Journal  of 
March,  1861,  together  with  a  reprint  of  Mr.  Logan's  letter,  and  also  a 


'■^ '■■■■■"':/' 


240 


part  of  our  pamphlet,  under  the  altered  and  false  title  *  of,  On  the  Pri- 
mordial Fauna  and  the  Taconic  system  of  Emmons,  in  a  letter  to  Prof. 
Bronn  of  Heidelberg . 

While  these  publications  were  in  progress  in  America,  M.  Barrande, 
in  the  Bulletin  de  la  Socie'te'  Ge'ologitjue  de  France,  Vol.  xviii.  p.  203, 
at  the  meetings  of  I^ov.,  1860,  and  Feb.,  1861,  gave  a  long,  elaborate, 
and  impartial  memoir,  entitled,  "  Documents  anciens  et  noiweaux  sur 
la  faune  primordiale  et  le  systcme  Taconique  en  Ame'rique,  with  two 
plates ;  in  which  he  gives  at  length  the  numerous,  sagacious,  and 
profound  observations  of  Dr.  Emmons  on  the  Taconic  system,  so  long 
kept  in  the  background. 

Professor  Agassiz,  who  has  contributed  much  to  the  enlargement  of 
our  views  and  notions  as  to  the  great  value  of  paleontological  charac- 
ters for  the  determination  of  the  relative  age  of  strata,  desirous  to  assist 
in  the  elucidation  of  the  dilliculty,  signalized  with  si'ch  a  masterly 
hand  by  M.  Barrande,  sent  me  to  Vermont  and  Canada  to  collect  all 
the  specimens  of  fossils,  and  all  the  facts  I  could  reach,  for  the  benefit 
of  his  Museum  of  Comparative  Zoology.  I  give  below  a  very  sum- 
mary resume  of  what  I  have  seen,  reserving  all  the  detailed  sections, 
new  fossils,  and  geological  maps,  ibr  a  longer  memoir  now  in  prepa- 
ration. 

I  must  begin  by  the  statement  that  the  Taconic  system  of  Dr. 
Emmons  is  the  true  base  of  the  sedimentary  strata  in  North  America, 
and  that  I  agree  in  the  main  with  all  the  observations,  sections,  and 
descriptions  of  fossils  of  Dr.  Emmons,  who,  in  establishing  the  founda- 
tion-stone of  the  pillar  of  American  Stratigraphy,  has  given  in  his 
different  memoirs  on  the  Taconic  system  the  most  difficult  and  impor- 
tant geological  works  which  have  ever  been  produced  on  this  side  of 
the  Atlantic. 

My  researches  were  principally  directed  toward  the  upper  part  of 
the  Taconic  series  and  the  LoAver  Silurian,  and  I  give  a  tabular  view, 
showing  the  succession  of  groups  of  strata.  This  I  was  able  to  make 
out  for  the  vicinity  of  Georgia,  St.  Albans,  Swanton,  Highgate-Springs, 
and  Phillipsburgh,  on  the  north-eastern  shore  of  Lake  Champlain. 

Lorraine  Shales.  —  This  group,  which  has  been  also  called  Pulaski 
Shales  and  Hudson  River  Group,  does  not  occur  at  Snake  Mountain, 
nor  in  the  vicinity  of  St.  Albans,  Georgia,  Swanton,  and  Highgate. 
Indeed,  I  did  not  find  a  single  trace  of  this  group  anywhere  on  the 
main  land  of  Vermont,  and  I  only  saw  it  on  the  peninsula  of  Alburgh, 
between  Missisquoi  Bay  and  Rouse's  Point,  where  it  presents  the  rocks 


I 


-.. 


*  I  regret  to  say  that  this  is  the  second  instance  since  1858  in  which  the  editors  of 
Silliman^s  Journal  have  not  only  appropriated  letters  belonging  to  me,  but  attrib- 
uted them  to  persons  who  have  had  nothing  whatever  to  do  with  them. 


241 


THEORETICAL     SECTION     OF     THE     UPPER      TACONIC     AND     I-OWER 
SILURIAN    ROCKS   OF   VERMONT. 


:s 
of 


i 

w 
H 
U 

CO 

PfS 

? 
O 
1^ 

OROUPS.                        FKKT.  j            LOCALITIES,    SUBDIVISIONS,  AND    t'OgglLB. 

1 

a. 

B 

a 

LonnAiNE  Shalbb. 

j    Alburgli  Peninsula. 

Utica  Slatk. 

40    1    Hijjhgate-Springs. 

Trbnton  Limestone. 

60 

Iligligute-Springs. 

Black  Kiveh  Guoup. 

40 

•»  At  the  base  a  blue  limestone,  very  fossil- 
iferous,  with  Ampyx  Halli;  2  feet,  lligh- 
gate-Springs. 

Calciperoub    Sand- 
stone. 

700 
to 
900 

.3.  Gray  and  blue  shales,  containing  nodules 
of  blue  limestone,  with  fossils;  about  150 
feet.    East  of  rUillipsburgh  (llillings). 

2.  Blue  and  black  limestone,  very  fossilifer- 
ous  (Bdihyurus  Snff'oriii);  about  300  feet. 
Phillipsburgh  ( Billings).    St.  Albans  liay. 

1.  Gray  and  almost  white  limestone,  con- 
taining numerous  veins  of  calc-spar,  mar- 
ble, and  magncsiau  limestone;  about  300 
feet.    Phillipsburgh  (Billings).    St.  Albans 
Bay.    Swanton. 

s 

a 

Overlie  the  Taconic  strata  in  discordance  of  stratification. 

M 

o 
< 

P5 
u 

;3 

roTSDAM  Sandstone. 

.300 
to 

400 

4.  Doloniitic  conglomerate;  30  feet.    Saint 
Albans. 

3.  Red  sandstone,  with  ConoeephnWes  Adam- 
si,  C.   Vutcanus  ;  80  feet.    Sa:-  e's  Mills.  St. 
Albans. 

2.  Dolomite;  150  to  200  fee- .     •  ixe's  Mills. 
Swanton.    St.  Albans. 

1.  White  and  red  sandstone;    0  feet.     St. 
Albans  Bay. 

i 

s 

B 
» 

LiNGULA  Flags. 

500 
to 
600 

Brown,  green,  and    blackish  slates,  with 
Lin!iul(T,  Orlhisina.  Orthis^Chrondites,  Grap- 
tolites.    Highgate-Springs. 

Georgia  Slates. 

500 
to 
600 

Gray,  black,  sandy  slates,  with  Pnmdoxides 
(  Olmelliis)  T/iompsoni ,  P.  Vermontana,  Pel- 
turn  liolopi/ifa,  Con.  Tencer,   Oholella  cingu- 
latn,  Ortliisina  festinaln,  Ourterella  antiquuta, 
Chrondites,  Fiingiis.  W.  Georgia.  Swanton. 

St.  Albans  Group. 

2500 
to 

3000 

Green,  brown,  and  reddish  slates,  contain- 
ing large  lenticular  masses  of  very  hard, 
whitish-gray  limestone.     Trilobites.    St. 
Albans.    Georgia  Centre. 

Quartzitc,  Conglomerates,  and  Ta'oose  slates. 
and  belonging  to  the  Lower  Taconic 


Between  St.  Albans  and  Fairfield, 


242 


and  fossils  which  characterize  it  at  Sandy  Creek,  the  typical  locality 
of  Jerterson  county,  in  the  State  of  New  York. 

Utlca  Slate.  —  The  only  locality  where  I  met  with  these  strata  was 
on  the  shore  of  Lake  Champlain,  a  short  distance  behind  the  hotel  of 
Highgate- Springs.  The  thickness  of  what  is  not  covered  by  the  water 
is  forty  feet;  they  have  been  overturned,  and  lie  below  the  Trenton 
Limestone.  Dr.  G.  M.  Hall,  of  Swanton,  has  found  this  group  on 
several  of  the  islands  in  the  middle  of  the  lake. 

Trenton  Limestone,  —  This  group,  with  its  usual  characters,  is  found 
at  Ilighgate-Springs. 

Black  River  Group.  —  Comprising  the  Black  River  limestone,  Birds- 
eye  limestone,  and  Chazy  limestone.  It  is  common  to  find  now  and 
then,  scattered  along  the  whole  line  from  Highgate-Springs  to  Bridge- 
port, in  small  patches,  lying  in  discordant  stratification  over  the  different 
divisions  of  the  upper  Taconic,  some  beds  of  limestone  of  this  group. 
The  thickness  seldom  reaches  forty  feet.  They  contain  numerous 
fossils  characteristic  of  the  group.  Localities  :  Ilighgate-Springs,  West 
Georgia  (near  Mr.  Parker's  house),  and  Snake  Mountain.  At  High- 
gate-Springs the  last  bed  of  the  Black  lliver  group  is  formed  of  a  hard, 
blue,  grayish  limestone,  two  feet  thick,  with  Ampyx  Ilalli,  very  fossilife- 
rous,  and  constituting  a  very  conspicuous  and  easy  point  de  repere. 

Calciferoiis  Sandrock.  —  Until  lately  this  group  was  not  considered 
of  the  importance  that  it  really  is,  and  it  is  due  mainly  to  the  researches 
of  Mr.  Billings,  of  Montreal,  that  we  have  at  last  come  to  a  true  knowl- 
edge and  understanding  of  its  characters,  and  the  great  place  it  occu- 
pies in  the  Lower  Silurian.  In  fact,  the  Calciferous  Sandrock  is  the 
base  of  the  Lower  Silurian,  and  contains  half  the  thickness  of  the  beds 
composing  the  Lower  Silurian  of  North  America.  In  the  Paleontol- 
ogy of  New  York,  by  James  Hall,  Vol.  i.,  thirteen  or  fourteen  fossils 
are  described  as  being  the  only  remains  of  organized  beings  found  in 
the  Calciferous  Sandstone,  whereas  now  Messrs.  Jewett^Billings,  G.  M. 
Hall,  Perry,  Farnsworth,  J.  Richardson,  J.  Bell,  and  myself,  have 
succeeded  in  collecting  from  this  group  in  Vermont,  New  York,  Canada, 
and  at  Belle  Isle  (Newfoundland),  more  fossils  than  in  all  the  other 
Lower  Silurian  groups  put  together,  —  that  is  to  say,  about  twelve 
hundred  species,  of  which  one  hundred  are  new  Trilobites.  To  any 
one,  however,  acquainted  with  the  different  Silurian  faunae  of  Europe, 
it  was  evident  that  the  second  fauna  of  North  America  had  not  been 
well  worked  out  by  the  Paleontologist  of  New  York,  and  that  at  least 
a  good  half  of  it  had  escaped  his  hasty  and  superficial  researches  in 
the  field  ;  so  that  this  discovery  of  numerous  fossils  belonging  to  the 
second  fauna  in  the  Calciferous  Sandstone,  however  sudden  it  might 
be,  was  not  unexpected  to  any  one  who  has  studied  the  different 
memoirs  of  Barrande  on  the  subject. 


I 

I 


24:i 


A  series  of  j?ray  and  bluo  shales,  (rontaininj^  nodulos  of  blue  lime- 
stono,  with  fossils  oljaracturistit;  of  thii  Cah-ifiTous  Sandrofk,  was  dis- 
covered in  Au;i;iist  last  by  Mr.  Hillincrs,  ten  miles  east  of  Phillips- 
burjjh,  on  the  road  to  Frelifrsbiirj»h,  in  Canada.  Mr.  Hillinjis  saw  it 
lying  over  the  limestone  that  forms  the  followintj;  snbdivision,  but  was 
unable  to  make  out  its  thickness,  and  its  junction  with  the  lllack  River 
group,  so  that  givinp;  about  one  hundred  and  fd'ty  feet  for  it  is  a  mere 
guess. 

The  second  sul)division  in  descending  the  8(!ries  has  been  called  by 
Mr.  Billings,  in  his  interesting  memoii",  entitleil.  On  some  RocLi  and 
FoKsits  occurring  near  Phillipshuryfi,  C<tn(vla  Ed^l  —  (see  the  Canadian 
Genloffhl,  August,  1861,  p.  ;U0,  Montreal,)  —  Blue,  Thin-hcdded  and 
Nodidar  Limestone.  As  Mr.  Billings  has  given  a  good  descri|)tion  of  it, 
I  will  not  repeat  it  here.  The  fossils  are  very  numerous  one  mile  east 
of  Phillipsburgh,  and  just  behind  the  houses  of  the  village  of  St. 
Albans  Bjy.  The  most  characteristic  are,  Camerefla  adci/'cra;  Orthis; 
Madnrea  mn/nlina;  Ophilda  sordida,  O.  leixita,  0.  complanata;  Eccu- 
liomphalus  Canadensis,  E.  intortus,  E.  spiralis ;  Pleurolomaria;  Mur- 
chisonia  ;  Hnlopeu  ;  Capului ;  Orlhoreras  ;  Ci/rtoceras ;  Nautilus ; 
Lituites  iinperator,  L.  Fanisworlhi ;  Rathi/urus  Saffordi,  B.  Cordai ; 
Amp/lion  Salteri ;  Asaphus;  Crinoids,  Corals  and  Fucoids. 

Below  this  subdivision,  and  passing  gradually  into  it  without  any  well 
defined  line  of  separation,  is  a  series  of  gray,  almost  white,  limestone, 
containing  numerous  veins  of  calc-spar,  white  marble,  and  magnesian 
limestone.  Mr.  Billings  has  called  it  Magnesian  limestone,  but  as  true 
dolomite  is  found  in  large  (Quantities  in  the  middle  of  the  Potsdam 
Sandstone  group,  I  think  this  name  will  have  to  be  changed.  The 
fossils  are  rare  in  this  lower  subdivision,  but  Dr.  G.  M.  Hall  has  found 
in  it  some  Cephalopods  and  Gasteropods  half  a  mile  south-east  of  Phil- 
lipsburgh. This  last  subdivision  was  very  plastic  when  first  deposited, 
for  it  re-covers  in  discordant  stratification  the  slates,  and  sometimes 
also  the  Potsdam  Sandstone  of  the  Taconic  system,  and  follows  all  the 
accidents  of  the  Taconic  strata,  as  though  they  were  covered  with  a 
sheet  of  paste  or  plastic  clay.  I  regard  it  as  the  bottom  rocks  of  the 
Silurian  system  in  North  America,  containing  the  second  fauna  of 
Barrande.  It  can  be  observed  at  Phillipsburgh,  on  the  shore  line,  east 
of  Swanton,  and  north  of  St.  Albans  Bay.  It  maybe  that  it  forms  the 
marble  of  Middlebury  and  Rutland,  but  I  am  unable  to  speak  with  any 
certainty,  as  it  requires  a  special  investigation,  which  I  have  been 
unable  to  make. 

The  Calciferous  Sandstone  always  lies  in  discordance  of  stratifica- 
tion on  the  different  groups  of  the  Upper  Taconic  Strata ;  sometimes 
the  discordance  is  40°,  generally  15°  to  20°,  and  the  direction  of  the 
tetes  de  couches,  or  strike,  as  it  is  called  in  English,  cuts  always  the 
direction  oi'  the  Taconic  strata,  at  an  average  angle  of  25°. 


244 


Potsdam  Sandstone.  —  In  Vermont  the  Potsdam  Snndstone  has  ex- 
actly the  Hame  aspect  and  conipoHitlon  as  at  I'otsdam,  in  the  State  of 
New  York.  Near  Saxe's  Mills,  a  mile  east  of  the  Ilighgate-Sprin^js, 
it  contains  two  species  of  Couocej^hitlitcs,  C.  Adinnsi  and  C.  Vulcnnus. 
Being  the  cai)ping  group  of  the  Taconic  in  the  reiwersement  (overturn) 
of  the  strata,  it  has  been  broken  into  pieces  and  narrow  parallel 
bands,  which  liave  rested  upon  the  more  inclined  strata  in  a  sort 
of  unconfoi-mablo  stratification,  very  apparent  everywhere,  scpieezing 
the  Lingula-flags  and  Georgia  Slates  near  the  point  of  contact,  and 
giving  them  for  about  two  feet  depth  a  sort  of  agitated  structure 
(structure  lourmoitee).  Theses  narrow  bands  of  Potsdam  Sandstone 
are  numerous  and  well  developed  west  of  Mr.  Parker's  farm  at  (icorgia, 
and  also  on  the  road  l)etween  St.  Albans  and  Swanton  ;  at  first  they 
appear  to  be  interstratified  with  the  Georgia  Slates,  but  they  are  not 
BO,  and  may  be  compared  to  the  steps  of  a  ladder  placed  over,  or 
even  a  little  wedged  into  the  (Georgia  Slates  and  Lingula-ilags.  This 
group  has  been  known  for  a  long  time  in  Vermont  by  the  name  of 
Red  SandrocL  It  is  found  all  the  way  from  Saxe's  Mills  to  Western 
Georgia.  It  forms  the  top  and  eastern  side  of  Snake  Mountain,  con- 
trary to  the  view  of  Dr.  ICmmons,  who  refers  these  Snake  Mountain 
rocks  to  the  Calciferous  Sandstone.  All  the  fossils  found  until  now  in 
the  Potsdam  Sandstone  of  Vermont  and  New  York  are  of  primordial 
form ;  and  there  is  also  a  great  break  and  dis<'ordance  of  stratification 
between  this  group  and  the  Lower  Silurian ;  and  I  think  the  opin- 
ion I  first  expressed  one  year  ago  is  fully  justified  by  paleontological 
and  stratigraphical  evidences. 

Below  the  Potsdam  Sandstone  lie  great  masses  of  slates,  four  or  five 
thousand  feet  thick,  which  for  convenience  I  should  divide  into  three 
parts.  No  regular  line  of  division  can  be  traced  between  these  three 
groups,  as  the  strata  pass  from  one  to  the  other  without  any  well 
marked  ditl'erence  ;  it  is  merely  for  the  fossils,  and  as  a  matter  of  con- 
venience, that  I  propose  the  division. 

Lingula-Jloffs.  —  The  upper  group,  or  Lingula-flags,  is  formed  of 
brown,  green,  and  blackish  slates,  five  or  six  hundred  feet  thick,  with 
numerous  lines  of  cleavage,  cutting  the  strata  in  all  sorts  of  direc- 
tions. In  some  parts  the  fossils  are  very  numerous,  and  I  found  at 
Highgate-Springs,  where  I  first  saw  them,  in  company  with  Dr.  Hall,  a 
quantity  of  Lingulce,  Ortliis,  Orthisina,  and  Chrondites.  The  Lingula 
is  new,  and  the  Orthisina  is  nearly  related  to,  if  not  identical  with, 
an  Orthisitia  quite  common  in  the  Lingula-Hags  of  Wales  in  Great 
Britain.  Mr.  Billings  informs  me  that  since  my  visit  there  he  found  at 
Phillipsburgh  some  Graptolites,  in  slates  near  the  shore  of  the  lake, 
which  I  consider  as  of  the  upper  group,  or  Lingula-flags. 

Georgia  Slates.  —  The  middle  group,  or  Georgia  Slates,  is  composed 


.1 


.. 


245 


of  pray  and  black  sandy  slates,  somotinips  passing  into  a  tnie  yellowish 
siindstont!,  with  nodules  ofoxidu  of  iron,  and  spots  ot'reil  oxide  of  iron 
on  some  slates.  Tiiickncss,  live  to  six  imndred  ieet.  In  tiiis  division, 
tifty  yards  from  tlie  liouse  of  Mr.  Xoali  E.  I'arker,  in  West  (leorjjia, 
the  eeiehratcd  (Jeorjiia  Trilolntes  wc^re  found.  They  were  discovered 
accidentally,  about  six  years  ajjo,  by  Mr.  Parker,  in  (puirrying  large 
slates  tor  a  floor.  Having  (bund  one  Trilobite,  and  not  knowing  what 
it  could  be,  Mr.  Parker  showtid  it  to  the  schoolmaster  of  the  village, 
who  wrote  at  once  to  the  late  Zadock  Thompson,  of  TJiirlington,  then 
State  Geologist  of  Vermont.  ]\Ir.  Thompson  immediately  visited  the 
([uarry,  and  made  a  collection  of  several  specimens  and  species;  unfor- 
tunately ho  died  a  short  time  after,  without  publishing  anything  about 
this  discovery.  The  specimens  having  been  jjlaotMl  in  the  hands  of 
Mr.  fJames  Hall,  that  jjaleontologist  described  and  figured  them  in  a 
memoir  under  the  very  odil  title  of  Trilohilea  nfthc.  Shales  of  the  Hud- 
son Rh'cr  Group:  Albany,  1H(;(».  It  was  this  title  that  startled  Mr.  Bar- 
rande  so  much,  anil  was  the  occasion  of  bringing  once  nxore  before  the 
world,  and  this  time  not  to  be  sujjpressed,  the  Taconie  system  of  my 
learned  friend  Dr.  Kinmons.  Mr.  James  Hall  does  not  give  a  single 
geological  fact  to  sustain  his  opinion  of  the  Hudson  River  group;  he  re- 
gards it  as  a  matter  of  eourac;,  beyond  all  doubt;  and  in  order  to  give  it 
a  sanction  which  will  make  all  discussion  useless,  he  calls  to  his  support 
the  testimony  of  Mr.  Logan  (who,  by  the  way,  has  never  visited  the 
locality),  and  adds,  as  overwhelming  proof,  that  "  it  would  be  quite 
superfluous  for  him  to  add  one  word  in  support  of  the  opinion  of 
the  most  able  stratigraphical  geologist  of  the  American  continent." 
The  only  other  geological  indication  tli;it  I  have  been  able  to  find  is  in 
SiUiman's  Journal  for  January,  1861,  p.  I'lh,  where  Mr.  James  D. 
Dana  calls  the  Georgia  rocks  "  metamorphic  bla(.'k  slates."  I  regret 
to  say  that  all  these  statements  and  opinions  are  erroneous;  there  is  no 
trace  of  the  Hudson  River  (/roup  at  Georgia,  nor  at  any  other  place  in 
the  vicinity,  and  I  was  unable  to  find  indications  of  metamorphisra  in 
any  of  the  rocks  tlwre,  for  at  least  three  miles  around  the  quarry  of 
Mr.  Parker.  The  fossils  are  not  numerous,  with  the  exception  of  the 
Chrondkes ;  and  the  Trilobites  are  certainly  much  less  common  there 
than  the  Paradoxides  Harlani  in  the  (juarry  of  Mr.  Haywood  at 
Braintree.  I  found  at  West  Georgia  the  three  Trilobites  described  by 
Mr.  James  Hall,  Paradoxides  (Olenellus)  Thompsoni,  P.  Vermonlana, 
Peltura  holopi/rja ;  and  besides  Obolella  cingulata,  a  Fungus,  Chron- 
dltes,  and  a  Bryozoon,  related  to  the  Graptopora  sociatis  (Salt.),  all 
primordial  fossils. 

Until  this  summer  West  Georgia  was  the  only  place  for  these  Trilo- 
bites. Two  other  localities  have  been  added  in  the  last  two  months. 
Dr.  G.  M.  Hall  and  Rev.  J.  B.  Perry  have  found  the  P.  Thompsoni, 


246 


P.  Vermontana,  Obolella  cingulata,  Orthisina  festinata,  Camerella  anti- 
quata,  Conocephnlites  ^eucer,  and  Ch-ondites,  a  mile  and  a  half  east  of 
the  vi^'age  of  Swanton ;  and  Mr.  James  lliohardson  has  collected 
specimens  of  the  same  Paradoxides  farther  east,  at  L'anse  au  Loup, 
on  the  north  shore  of  the  straits  of  Belle  Isle,  Labrador ;  (see  Neiv 
Species  of  Lower  Silurian  Fossils,  by  E.  Billings.  Montreal,  Nov.,  1861). 

Saint  Albans  Group.  —  The  road  between  St.  Albans  and  Georgia, 
and  thence  from  Georgia  to  Mr.  Parker's  house,  lies  all  the  way  on 
green,  brown  and  reddish  slates,  containing  now  and  then  large  lenti- 
cular masses  of  very  hard,  whitish-gray  limestone.  Thickness,  be- 
tween twenty-five  hundred  and  three  thousand  feet.  I  did  not  find 
any  fossils,  although  I  heard  of  one  specimen  of  Trilobite  picked  up 
behind  the  town  of  St.  Albans  by  an  inhabitant,  nor  was  I  able  to 
see  that  specimen.  The  reddish  slates,  which  are  not  well  developed 
in  Vermont,  as  regards  the  red  color  of  the  rocks,  lie  at  the  base  of 
the  upper  Taconic  strata.  Tiicy  are  worthy  of  notice,  as  containing 
the  veins  of  sulphuret  and  copper  pyrites  of  the  Acton  mines,  in 
Canada,  and  the  Bruce  and  Wallace  mines  of  Lake  Huron. 

Below  the  St.  Albans  group  are  ([uartzite,  conglomerates,  talcose 
slates,  clay  slates,  mica-schist,  and  gneiss,  with  intercalation  of  beds 
and  lenticular  masses  of  crystalline  limestone,  resting  on  the  unstrati- 
fied  and  oldest  crystalline  rocks  of  the  AVhite  ^Mountains,  and  compos- 
ing the  Lower  Taconic  system.  Dr.  Emmons  did  not  i)ut  in  his  Lower 
Taconic  the  mica-schist  and  gneiss,  which  form  the  central  and  east- 
ern part  of  Vermont,  but  on  a  close  examination  of  the  subject  in  the 
vicinity  of  Rutland,  Bolton,  and  Island  Pond,  I  have  come  to  the  con- 
clusion that  these  rocks  have  a  stratified  and  sedimentary  origin,  and 
that  they  are  the  base  of  the  Taconic  system.  All  the  strata  of  the 
Lower  Taconic  system  are  more  or  less  metamorphic,  especially  at  the 
base  ;  —  the  metamorphism  produced  by  the  action  of  mineral  springs 
during  the  deposits,  together  with  pressure  caused  by  the  divers  dislo- 
cations to  which  they  were  aflerward  submitted.  The  Lower  Taconic 
is  at  least  ten  thousand  feet  thick,  making  fifteen  thousand  feet  the 
minimum  for  the  Taconic  system  of  Vermont.  It  is  difficult  to  give 
the  thickness  of  the  strata  with  any  exactness,  as  the  Green  Mountains 
present  a  fan-like  structure,  similar  to  that  of  the  Alps  and  Pyrenees. 

Twelve  years  after  the  discovery  and  description  of  the  Taconic 
system,  Mr.  Logan,  having  met  with  some  of  the  Taconic  rocks  on  the 
southern  edge  of  the  Laurcntine  Mountains,  between  the  Saguenay 
River  and  the  Bruce  mine  on  Lake  Huron,  and  overlooking  entirely 
the  researches  of  Dr.  Emmons,  proposed  to  introduce  into  the  table  of 
the  American  strata  two  new  systems,  which  he  called  the  lMure)ttian 
and  Iluronian  systems ;  (see  Esquisse  Geologique  du  Canada,  Paris, 
1855).     The  Laurentian  system  is  composed  of  the  Lower  Taconic,  to 


J 


247 


which  are  added  all  the  unstratified  crystalline  rocks  forming  the  centre 
of  the  Laurentine  Mountains,  such  as  granite,  syenite,  diorite  and 
porphyry,  mixing  together  strata  and  eruptive  rocks,  an  attempt  which 
was  unexpected  from  a  stratigraphical  geologist.  His  Huronian 
system  is  formed  of  a  mixture  of  the  St.  Albans  group  of  the  Upper 
Taconic,  with  the  Triassic  rocks  of  Lake  Superior,  the  trap  native- 
copper  bearing  rocks  of  Point  Keeweenaw,  and  the  dioritic  dyke  con- 
taining the  copper  pyrites  of  Bruce  mine  on  Lake  Huron. 

The  different  dislocations  which  have  affected  the  rocks  of  the 
vicinity  of  Quebec  have  not  brought  to  light  the  complete  series  of 
the  Taconic  nor  of  the  Lo.  dr  Silurian,  and  the  difference  of  opinion 
that  exists  between  Mr.  Logan  and  myself  is  partly  owing  to  this 
want.  In  his  Remarks  on  the  Fauna  of  the  Quebec  Group  of  Rocks  and 
the  Primordial  Zone  of  Canada,  Jan.,  1861,  and  in  his  Considerations 
relating  to  the  Quebec  Group,  May,  1861,  Mr.  Logan  gives  the  following 
series  for  the  vicinity  of  Quebec  :  — 

u^.  —  Dark  gray  shales  and  sandstones  ("Hudson  River). 

u^  —  Black  shales  (Utica). 

b.  —  Limestone  (Birdseye,  Black  River,  and  Trenton). 


►  Quebec  Group. 


q".  —  Sandstone  and  red  shales  (Sillery). 

q".  —  Red  and  green  shales. 

q''.  —  Green  and  gray  shales  a  id  sandstones. 

q^  —  Sandstones  and  magnesian  conglomerates. 

q^  —  Green  shales. 

q^  —  Magnesian  conglomerates  and  shales. 

p^— Sandstones.  I  Potsdam, 

p^  —  Black  shales  and  limestones.    > 
g.  —  Gneiss  (Laurentian). 

All  the  fossils  found  al  Point  Levi  are  placed  by  Mr.  Logan  in  a 
single  group  of  strata,  which  he  calls  the  Quebec  group.  He  speaks  also 
several  times  of  shales  and  limestones  beneath  the  Quebec  group, 
which  he  considers  as  deep-water  deposits  of  the  Potsdam  Sandstone. 
Unhappily  he  does  not  give  any  precise  localities  or  section  at  Quebec 
or  Point  Levi  where  that  Potsdam  may  be  found,  and  I  was  unable 
to  discover  what  strata  he  thus  names.  But  wherever  these  strata 
may  be  located,  he  says  that  he  found  no  fossils  in  them  in  Canada, 
"  but  that  the  shales  resemble  those  in  which  Oleni  have  been  found  in 
Georgia."  So  that  Mr.  Logan  considers  the  Georgia  Slates  and  the 
Potsdam  Sandstone  as  the  same  group,  one  being  a  deep-water  deposit 
and  the  other  a  coast  deposit.  I  will  only  remark  that  at  Mr.  Parker's 
house,  in  Georgia,  the  two  groups  are  found  one  above  the  other. 

Mr.  James  Hall,  in  his  last  descriptions  of  the  Georgia  Trilobites 
(Thirteenth  Annual  Repurl  of  the  Stale  Cabinet  of  Natural  History 


248 


of  New  York,  1861),  overlooking  the  remarks  of  Mr.  Logan  on  the 
Georgia  Slates,  includes  the  Georgia  Slates  in  the  Quebec  group,  adding 
new  contusion  to  an  already  very  difiuse  explanation. 

In  a  tabular  view  of  my  observations  in  the  vicinity  of  Quebec,  we 
shall  have  the  following  theoretical  section :  — 

THEOUETICAL    SECTION     OF   THE     KOCKS   OF   THE   VICIXITY  OF 

QUEBEC. 


OliOL'l'S. 

FEET. 

LOOALIIIES,  SUBDIVISIONS,  FOSSILS. 

•< 

H 

on 

K 

U 

o 

Lorraine  Shales. 

Not  seen. 

§ 

• 

Utica  Slate. 

40 

Montmorency  Falls. 

Tbemton  Limbstoke. 

30 

Jlontmorency  Falls,  Beaufort,  and  Indian 
Lorette. 

Black  Biver  Group. 

Not  seen. 

Calciferocs    Sand- 
stone. 

600 

a.  Blue  schistose  marls,  interstratifled  wi(h 
conglomerates  and  blue  limestone.    Com- 
pound  Gmptolites.    Citadel,  City  of  Que- 
bec, and  Point  Levi. 

6.  Gray   slates,   sometimes   blackish,  with 
alternation  of  yellow  sandstone,  magne- 
sian  conglomerate,  and  20  or  30  feet  of 
gray  limestone.    The  limestone  is  very 
iossiliferous :  Bathyurus   Saffordi,  B.  Cor- 
tlai,  EccuUomvhalus  Canadensis,  Camerdla 
calcifera,  etc.  ferre  du  Cure  at  Point  Levi. 

The  lower  part  of  the  group  is  not  visible. 

M 

z 
o 
o 
< 

Potsdam  Sandstone. 

Not  seen. 

1 

i 

a 

LiNGULA  Flags. 

Not  seen. 

Georgia  Slates. 

Not  seen. 

St.  Albans  Group. 

3000 

a.  Green,  brown,  and  black  slates  of  Gil- 
mor  wharf,  east  of  Point  Levi,  and  also 
on  the  road  to  Arlaka.    Containing  the 
large   lenticular   mass   of  whitish  gray 
limestone  of  La  Redoute  or  Guay  quar- 
ries.    The  Kedoute  limestone  contains: 
Dikellocephalus,  Conor.ephaliles,  Menoceph- 
alus,  Arionellus,  Orthisina,  Capulus  and  Cri- 
noUts. 

b.  Sillery  and   Chaudi6re  red  slates   and 
sandstones. 

4 


Quartzites  of  Montmorency  Falls, 
mined. 


Its  position  in  the  Lower  Taconio  still  undeter- 


249 


Lorraine  Shales  or  Hudson  River  Group.  —  Mr.  Logan,  in  his  section 
from  Montmorency  to  the  Island  of  Orleans,  regards  the  bed  of  the 
St.  Lawrence  as  entirely  formed  by  dark  gray  shales  and  sandstones, 
which  he  considers  of  the  age  of  the  Hudson  River  group.  Having 
no  diving  apparatus  at  my  disposition,  I  was  unable  to  follow  him  to 
the  bottom  of  the  St.  Lawrence.  If  this  group  really  exists  in  the 
vicinity  of  Quebec,  it  will  be  brought  out  by  a  careful  examination 
of  all  the  strata  between  Ste.  Foix  and  Indian  Lorette. 

Utica  Slates.  —  Dr.  Emmons,  in  his  Geolor/y  of  New  York,  1842,  p. 
117,  refers  the  slates  of  Montmorency  Falls  to  the  Utica  Slates,  having 
found  there  the  characteristic  Trilobites  of  Triarthus  Beckii.  Dr. 
Bigsby  also  calls  them  Utica  slates  {On  the  Geolor/y  of  Quebec  and  its 
environs,  1853),  and  so  did,  after  their  example,  Mr.  Logan.  In  my 
short  exploration  of  1849,  I  erroneously  considered  those  black  slates 
of  Montmorency  Falls  as  older  than  the  Trenton  Limestone  forming 
the  summit  of  the  falls ;  but  at  my  recent  visit  I  found  the  opinion  of 
the  geologist  above  named  to  be  correct. 

Trenton  Limestone. —  The  thirty  feet  of  limestone  at  the  top  of  Mont- 
morency Falls,  and  at  the  foot  of  the  precipice  immediately  in  contact 
with  the  quartzite,  are  of  the  Trenton  Limestone  age,  as  Mr.  Logan  has 
stated  in  his  description  of  Montmorency  formations ;  fossils  are  very 
abundant  in  both  places. 

Black  River  Group.  —  I  was  unable  to  refer  any  strata  to  the  subdi- 
visions of  this  group.  Mr.  Logan  does  not  give  any  special  localities 
for  it,  having  only  put  it  in  his  diagram  and  theoretical  section  without 
other  notice. 

Calciferous  Sandstone.  —  This  group  is  composed,  at  the  summit,  of 
blue  schistose  marls,  interstratified  with  thin  bedded  limestonos,  blue 
and  sometimes  almost  black,  and  large  masses  of  conglomerate,  the  size 
of  the  rounded  pebble  attaining  even  that  of  the  true  boulder.  In  this 
upper  part,  especially  in  the  cliff  on  the  road  from  the  ferry  to  Notre 
Dame  church  at  Point  Levi,  are  found  a  quantity  of  the  celebrated 
compound  Graptolida;.  The  citadel  and  the  old  town  of  Quebec  are 
built  on  it.  Then  there  is  a  succession  of  gray  slates,  sometimes 
almost  black,  with  alternations  of  yellowish  coarse  sandstone,  magne- 
sian  conglomerate,  and  twenty  or  thirty  feet  of  a  gray  limestone,  brec- 
ciated,  hard,  and  very  fossiliferous.  I  did  not  see  the  lower  part  of 
the  Calciferous  Sandstone ;  perhaps  it  has  been  concealed  by  the  dislo- 
cations, or  was  never  deposited  in  this  part  of  Canada.  The  thick- 
ness of  the  whole  is  about  six  hundred  feet.  This  number  appears  at 
first  a  small  one,  but  if  we  take  into  consideration  the  numerous  fold- 
ings of  this  deposit,  and  also  the  narrow  band  it  forms,  it  will  be  seen 
to  be  sufficient,  for  the  ridge  which  it  forms  is  never  more  than  a  mile 
and  a  half  in  width,  cxtcndiii'r  from  Quebec  to  the  Plains  of  Abra- 


250 


ham,  Claremont,  and  Cape  Rouge,  the  extremity  of  Point  Levi,  and  a 
little  of  the  clitf  west  of  it,  and  finally  a  part  of  the  island  of  Orleans. 
It  rests  unconformably  upon  the  different  subdivisions  of  the  St. 
Albans  group  ;  that  is  to  say,  on  the  Taconie  slates  of  Gilmor  Wharf, 
the  lledoute  limestone,  and  the  Sillery  and  Chaudi^re  red  rocks. 
This  uneonformability  is  somewhat  difficult  to  make  out,  because  the 
strata  have  been  so  dislocated,  folded,  and  squeezed,  that  they  oflen 
appear  as  if  they  lay  below  the  St.  Albans  group  instead  of  being 
above,  as  they  are  in  fact.  But  patient  and  numerous  observations 
made  with  a  theodolite,  or  a  good  compass,  will  clear  up  all  the 
difficulty. 

In  Remnrkson  the  Fauna  of  the  Quebec  Group,  &c.,  Mr.  Logan  gives 
some  details,  calling  separate  exposures  or  outcrops.  A,  A^,  A^,  A", 
A*,  B',  B",  and  B',  and  considering  the  whole  as  one  group  of  strata. 
I  tried  without  success  to  understand  his  explanation  when  I  was  at 
Point  Levi,  his  memoir  in  one  hand  and  mv  hammer  in  the  other. 
The  only  thing  I  was  able  to  make  out  was :  1st,  that  what  he  calls  the 
more  northern  outcrop.  A**,  was  mainly  the  quarries  of  the  Notary 
Guay,  or  the  Redoute  limestone ;  I  say  mainly,  for  other  strata  may  be 
included  in  it,  of  limestone  and  conglomerate  which  surround  the  len- 
ticular mass  of  the  Redoute*  ;  2d,  that  his  outcrops  A\  A'',  A*,  B',  B^, 
and  B'',  were  a  single  group  of  strata,  with  repetition  of  several  beds 
by  folding,  situated  between  the  churches  of  St.  Joseph  and  Notre 
Dame,  a  little  east  of  that  line,  and  in  a  parcel  of  ground  called  by 
the  Canadians  Terre  du  Cure  (land  of  the  Curate  of  St.  Joseph)  ;  3d, 
the  cliff  A  is  exposed  very  well  on  the  road  leading  from  the  ferry  to 
Notre  Dame  church. 

Mr.  Logan  includes  also  in  his  Quebec  group  the  Sillery  red  shales 
and  sandstones,  the  whole  having,  perhaps,  a  thickness  of  five  or  seven 
thousand  feet,  and  regards  it  as  the  equivalent  of  the  Calciferous  Sand- 
stone and  Chazy  Limestone.  The  Chazy  Limestone  is  a  small  subdi- 
vision of  the  Black  River  group,  and  I  did  not  see  it,  or  any  equiva- 
lent of  it.  The  cliff  A  is  in  part  subdivision  a  of  the  Calciferous 
Sandstone  of  my  tabular  view.  The  outcrops  A^  A^,  A*,  B\  B',  and 
B*,  form  entirely  my  subdivision  h ;  I  will  call  them  strata  de  la  terre 
du  Cure.  The  fossils  are  very  numerous  in  several  beds,  especially  in 
some  of  the  brecciated  limestone ;  the  most  common  are :  Bathyurus 
Saffordi,  B.  Cordai,  B.  bituberculatus,  B.  quadratus ;  Cheirurus  Apollo, 
C.  Eryx ;  Aynostus  ;  Ecculiomphalus  Canadensis,  E.  intortus ;  Holopea 
dilucula ;  Pleurotomaria ;  Murchisonia ;  Orthoceras;  Cyrtoceras;  Orthis; 
Camerella  calcifera,  etc.,  all  belonging  to  the  second  fauna.  Mr.  Logan 


^ 


*  So  called  by  the  older  Canadians  because  there  was  a  Redoubt  there  during  the 
last  French  war. 


i 


251 


names  several  fossils,  especially  Trilobites,  BatJtyurus  and  Menocepha- 
lus,  which  are  common  to  the  outcrops  AS  A*,  A*,  BS  B",  and  B^  (strata 
de  la  terre  du  Cure)  and  the  outcrop  A^  but  I  did  not  find  any ;  it 
may  be  that  some  boulders  and  pebbles  of  A",  or  la  Redoute  Limestone, 
are  enclosed  in  the  conglomerates  of  the  different  beds  of  the  strata  de 
la  terre  du  Curd. 

The  outcrop  A*  is  entirely  distinct  from  the  others.  It  is  true  that 
La  Redoute  is  almost  entirely  surrounded  by  small  bands  of  Calcife- 
rous  Sandstone,  that  form  as  it  were  the  frame  of  a  small  island,  but 
such  accidents  are  not  rare  in  much  disturbed  and  dislocated  coun- 
tries, and  it  is  not  difficult  to  sec  that  La  Redoute  is  independent  of 
all  the  other  hills  of  Point  Levi,  forming  a  conspicuous  landmark, 
which  can  be  seen  from  all  the  environs  of  Quebec,  and  having  a 
north  and  south  or  meridian  direction,  in  common  -with  the  whole  of 
the  Green  Mountain  system,  which  put  an  end  to  the  Taconic  deposits, 
•while  the  other  hills  of  Point  Levi  and  Quebec  run  north-east  and 
south-west.  The  strata  de  la  terre  du  Curd  do  not  include,  I  think,  all 
the  Calciferous  Sandstone,  as  it  is  developed  in  Vermont  and  Phillips- 
burgh  ;  the  lower  part,  or  white  limestone  of  Phillipsburgh  shore,  is 
wanting  here. 

Potsdam  Sandstone.  —  I  did  not  see  any  rocks  in  the  vicinity  of 
Quebec  which  I  can  refer  to  this  capping  group  of  the  Taconic 
system. 

Lingula-Jlags.  —  Not  seen. 

Georgia  Slates.  —  Not  seen. 

<S^  Albans  Group.  -^  This  lower  group  of  the  upper  Taconic  is  well 
developed  on  the  south  shore  of  the  St.  Lawrence,  which  it  occupies 
almost  entirely,  with  the  exception  of  one  or  two  miles  at  Point  Levi. 
It  extends  far  into  the  interior.  Its  thickness  is  at  least  three  thousand 
feet.  The  upper  part  is  composed  of  green,  brown,  and  black  slates, 
affected  by  numerous  lines  of  cleavage,  and  can  be  seen  very  well 
developed  near  the  Gilmor  Wharf,  east  of  Point  Levi,  also  on  the  road 
from  St.  Joseph's  church  to  Arlaka,  at  one  mile  from  the  church.  I 
consider  the  Redoute  Limestone,  or  quarries  of  the  Notary  Guay,  as 
forming  a  lenticular  mass  inclosed  in  them,  similar  to  one  that  I 
observed  at  St.  Albans.  I  did  not  find  any  fossils  in  the  slates,  except 
the  Chrondites,  so  common  and  characteristic  of  all  the  upper  Taconic 
slates.  The  Redoute  Limestone  presents  a  highly  interesting  fauna. 
The  strata  are  almost  perpendicular,  with  a  direction  almost  due  north, 
and  a  deviation  to  the  east  of  5°  or  7°.  The  stratification  is  indistinct, 
as  it  always  is  with  lenticular  masses.  The  limestone  is  gray,  almost 
white,  very  hard,  sometimes  oolitic,  with  little  veins  of  chalcedony.  Its 
whole  thickness  cannot  be  less  than  eighty  or  one  hundred  feet.  In 
some  of  the  strata  fossil  remains  are  numerous,  but  composed  only  of 


262 


fragments,  chiefly  heads  and  pyffidia  of  Trilobites ;  and  it  is  very  diflicult 
to  obtain  specimens  on  account  of  the  great  hardness  of  the  stone.  I 
succeeded,  however,  in  collecting  the  following  species :  Conocej)Tia- 
lites  Zenkeri;  Dikellocephalun  moffnijicm,  D.  planlfrons,  D.  inegalops, 
D.  cristatus ;  pygidia  of  a  Dikellocephalus  not  named  by  Billings,  but 
figured  No.  11  and  12;  Arionellus  cylindriciis,  A.  suhclavatus ;  Meno- 
cephalus  Sedgetoicki,  Menocephalus  gldbosus ;  a  large  Capulus,  an 
Orthisina,  and  the  stems  and  even  the  foot  of  a  Crinoid. 

All  the  known  species  of  the  Rcdoute  limestone  have  been  described 
in  a  masterly  manner  by  Mr.  Billings  in  his  memoir,  On  some  species 
of  Fossils  from  the  limestone  near  Point  Levi,  opposite  Quebec,  August, 
1860.  I  did  not  find  the  Dikellocephalus  Belli  and  D.  Oweni,  nor 
Agnostus  Americanus,  A.  Orion  and  A.  Canadensis,  which  Mr.  Bil- 
lings describes  as  part  of  his  fauna  of  Limestone  No.  1.  Without 
touching  the  stratigraphical  question,  Mr.  Billings  separates  the  species 
under  the  heads  of  Limestones  Nos.  1,  2,  3,  and  4.  His  numbers  2,  3, 
and  4,  are  evidently  what  I  call  the  Calciferous  Sandstone  strata,  and 
his  No.  1  represents  in  part  the  Redoute  Limestone.  I  say  in  part,  for, 
perhaps,  he  has  put  in  No.  1  some  specimens  resembling  those  of  the 
Redoute  Limestone,  especially  when  broken  in  very  small  fragments, 
that  really  belong  to  the  strata  de  la  terre  du  Curd.  For  instance,  I 
found  a  good  specimen  of  his  Bathyurus  bituberculatus,  not  at  the 
Redoute,  but  at  the  terre  du  Cure',  and  I  did  not  find  a  single  speci- 
men or  trace  of  the  genus  Bathyurus  in  the  Redoute  Limestone  ;  con- 
sequently my  observations  in  the  field  do  not  lead  me  to  consider  the 
genus  Bathyurus  as  a  primordial  one ;  it  belongs  exclusively  to  the 
lower  part  of  the  second  fauna.  According  to  my  observations,  the 
fauna  of  the  Redoute  Limestone  is  entirely  primordial,  without  any 
mixture  whatever  of  fossils  of  the  second  fauna,  being  limited  to  the 
genera  Conocephalites,  Dikellocephalus,  Arionellus,  Menocejjhulus, 
Captdus,  Orthisina,  and  a  Crinoid,  which  characterize  the  primordial 
fauna  in  America  as  well  as  in  Europe. 

The  inferior  part  of  the  St.  Albans  group  is  formed  by  what  has 
been  called  the  Sillery  and  Chaudiere  red  shales  and  sandstones,  in 
which  no  fossils  have  as  yet  been  found.  In  Canada  this  part  of  the 
group  is  much  more  developed  than  in  Vermont,  or  perhaps  the  differ- 
ence in  colors  is  due  to  metamorphism  in  Vermont. 

Finally,  there  is  a  beautiful  quartzite  at  the  falls  of  Montmorency, 
which  Mr.  Logan,  for  an  unknown  reason,  continues  to  call  Lauren- 
tian  gneiss.  It  forms  the  bed  of  the  Montmorency  river  and  the 
chasm  of  the  precipice.  It  is  indistinctly  stratified  by  beds  from  ten 
Kfl>r  to  twelve  feet  thick,  very  pEkfk  and  compact,  and  has  all  the  characters 
of  a  metamorphic  sandstone  or  true  quartzite.  Direction  or  strike  N. 
45°  E.  to  8.  45°  W.,  dipping  south-east  at  an  angle  of  80  or  85 
deiirces. 


253 


4 


Such  is  the  series  of  rocks  seen  by  me  in  the  vicinity  of  Quebec. 
Mr.  Logan  says,  "  from  the  physical  structure  alone  no  person  would 
suspect  the  break  that  must  exist  in  the  neighborhood  of  Quebec ;  and 
•without  the  evidence  of  the  fossils  every  one  would  be  authorized  to 
deny  it ; "  thus  throwing  on  Paleontology  all  the  mistakes  made  atid  all 
the  difficulties  accumulated  in  his  Quebec  Group.  I  ask  permission  to 
say  that  the  Stratigraphical  and  Lithological  differences  between  the 
Silurian  and  Taconic  rocks  of  the  vicinity  of  Quebec  are  to  me  at 
least  as  great  and  as  plain  as  the  Paleontological  ones ;  and  that  I  find 
no  facts  whatever  which  show  any  conflict  between  Paleontology  and 
Stratigraphy. 

It  is  doubtful  if  all  the  shales  between  the  chasm  of  Montmorency 
Falls  and  the  waters  of  the  St.  Lawrence  are  of  the  Utica  Slate  age ; 
the  Graptolitas  bicornis  and  G.  pristis  are  found  in  the  black  shales 
near  their  contact  with  the  Trenton  Limestone,  but  as  yet  no  fossils 
have  been  found  in  the  gray  shales.  In  the  ravine  east  of  the  Falls, 
there  is  probably  a  fault  between  the  black  and  gray  Shales ;  the 
dipping  of  the  Trenton  Limestone,  the  black  Shales  and  gray  Shales, 
disagrees,  and  varies  from  fifteen  to  eighty  degrees,  in  a  space  of  less 
than  150  feet.  I  am  inclined  to  consider  the  gray  Shales  as  the  upper 
part  of  the  Calcif'erous  Sandstone  group,  but  it  will  require  further 
investigations  in  the  field  to  determine  the  true  stratigraphical  struc- 
ture of  Montmorency  Falls. 


4 


(• 


